The original owner had a wiring harness installed at a local UHaul. Nothing fancy. They tapped in to the wires and housed the unit behind the rear access panel. (behind the spare tire). This has worked fine since I purchased it in 96.

Now..my problem. I borrowed a camper over the weekend that required a 6-pole harness. I found one at a junk yard and made connectors for it to plug into the existing 4-pole. I tested at home, and with the exception of the left rear running light on the trailer, all lights worked. When I made it to the campground, I noticed that the running lights on the camper were no longer working and that the left rear tail light (the one the wiring harness was tapped into) was not working either. The right rear on the vehicle works fine. All other lights in the left rear housing (backup, turn, side marker) work fine. As expected, the wiring harness pole for the running lights is not getting any juice either.

Where could my problem be? It appears that there is not power making it back to the driver-side taillight. But, I am not receiving a "Rear Lamp Failure" as I had in the past when bulbs have blown. Could my problem be with the Bulb Failure Module?

After further testing when I returned home, I'm noticing that the left rear tail light on the trailer seems to have a leaky ground. Don't know if that might help.

fuses? i dont think it runs on its own relay... na... replace the bulb and see if all the trailer lights work.. ma b its like cristmas lights?_________________RE,adj tb,cold air,str8 pipe to flowmaster,242,boredTBwspacer, msdboxwirescoilpump,moparpcm, Efan,5.9alte,sytem2sick,tirerack,oba

well have you considered taking the harness out and wiring it back to stock?_________________RE,adj tb,cold air,str8 pipe to flowmaster,242,boredTBwspacer, msdboxwirescoilpump,moparpcm, Efan,5.9alte,sytem2sick,tirerack,oba

Check the socket itself. Those damn sockets are notorious for cracking and drying up and breaking by themselves, just from vibration. Put a little MORE heat from amperage draw and...... u get the picture. Use a tester and check the actual wiring to the socket and continuity tester and double check your bulb too. Just thinking Occam's Razor may apply. Good Luck.

Replacing the Lamp Out Module did the trick. I pulled the part from a 93 GC at the local pull-a-part and things are working fine now. Before another problem occurs, I'm going to install a modulite system for my trailer harness.